Sunday, 30 October 2011

Natural building course South Africa

I took part in a week long natural building course in Berg-En-Dal eco-village in South Africa, I had an amazing time, learnt a lot and felt it gave me the knowledge and support to now start building our family home. 

here is an overview of what was taught on the course:

Zone Zero (home) and Zone One (surrounding garden) integration and climate mitigation Green technology introduction.
-Basic site layout and measuring
-Passive solar design
-Mud brick /Adobe
-Rammed earth
-Straw bale
-Compressed earth block
-Environmental and social impact of building
making a stone and cob/lime mortar foundation

Building an adobe brick wall

For anyone who is interested in natural building or building your own home, I feel a building course is really useful to do before you start. For those of you living in southern africa I would recommend the course at Berg-En-Dal eco-village, the link for their website is below:      

Tuesday, 25 October 2011

Testing, Testing 1 2 3 4 5 6 7 8 9 10 11 12

The first thing I had to do was test the soil on and around our plot to see if it was suitable for building with cob. A local carpenter made brick moulds to my specifications from wood from forestry land. We employed a young man from our village to collect different sands and clay in his scotch cart from areas close by. Cob needs to have the right proportions of clay and sand, we found there was a very good clay deposit just below our plot, the sand on the plot is very fine so river sand was also collected as a good particle range is needed. Straw is essential for tensile strength in the mix, wheat is supposed to be the best. There is no farming of wheat in our area so for the tests I used wild grass that had been baled once it had dispersed it's seeds.
I made 12 mixes, using different proportions of sand and clay, the most fun method of mixing cob is on a  tarp with your feet. All the sand water and clay are mixed with your feet and then by rolling the tarp in different directions to make sure everything is well mixed, the straw is added last.
"You know your job, you dance like an elephant" 'Yabani' on seeing me mixing cob with my feet!

The next step was to make bricks using the brick moulds, this is only for testing the strength of the mix as cob is applied wet to the foundation/stem wall. I made the bricks numbering each mix and small balls to test the compressive strength.

After a week of drying(and turning every couple of days) the bricks were ready to test. To do this I dropped the bricks on a hard surface to see how and if they broke! Most of them crack at least a bit, but I found the perfect mix!! 2 1/2 buckets of pit sand(dug from the plot) 1 1/2 buckets of river sand and 1 bucket of clay, plus the straw makes a very strong mix, so I am very pleased!

Towards a more sustainable life

I have been living in and around Hwange National Park Zimbabwe for almost 5 years with my husband and our 3 year old son. At the beginning of this year we decided to take the plunge and do something we had talked about for a long time. We visited our chief who is the traditional leader of this area and asked if we could live in the communal area on the edge of Hwange national park. The majority of the population of Zimbabwe live in rural communal lands, the chief allocates land to each family. We decided that we wanted to do this for several reasons. We want to live a more sustainable lifestyle where we can grow our own food and live  more in tune with nature. We want to put our money where our mouth is and not just talk about living more responsibly but actually do it. We want to be part of the community with which we have lived along side but still on the outside, a community that faces constant difficulties one of which is living with wildlife. Hwange National park is not fenced so wildlife moves freely into the communal areas where people are living. Predators such as lions, hyaenas, leopards and Jackals kill livestock such as cows and goats. Elephants, bushpigs and baboons raid people's crops. These animals destroy people’s livelihoods and in retaliation snares (wire traps) or poison are sometimes used to kill the animals. We don’t feel we have the answers to end this conflict but we feel that living the same difficulties for ourselves we may be in a better position to help find and implement solutions, which can help both people and wildlife.

Now for the cob bit…

As part of our desire to live a more sustainable life, I have been researching natural building techniques for the past year. There are many fascinating techniques some of which have worked for centuries others are new ideas, cob, straw-bale, rammed earth, sand bag houses to name a few. It is impossible to build a house with zero environmental impact but moving away from processed materials that require a huge amount of heat from fossil fuels to process and transport, is the beginning. Trying to use as many materials directly from the land and local skills and labour is the target! From all the techniques I researched and after spending a week in South Africa on a practical natural building course, my mind was made up, it had to be cob! Cob is a method, which has been used in many countries for centuries; cob is basically a mix of sand, clay, straw and water and is applied wet to the foundation or stem wall. This method appealed to me more than any other natural building technique because of how versatile and sculptural it is. The course had given me the confidence to believe I could start to build my own home from mud!